NPC can't fish, no message about lack of fish, or lack of tool

I give NPC a fishing rod, designate a 1x1 shallow water square by the river, and tell him “Fishing in a zone”. The message log immediately shows that NPC completes with the task. I don’t see any fish, nor any message about lack of fish, or lack of tool. I then get the rod and fish there myself. I get a fish. What’s the problem here?

update: I make a loot:tool zone, put an axe there, and make a chop tree zone, and ask NPC to chop tree. It works. Then I make a loot:tool zone, put the fishing rod there, and redraw the fishing spot. Still is the message “NPC completed the task” while the task is not worked on.

Is the zone within the reality bubble (60 tile radius around the PC)?

Some companion activities can resume when the reality bubble returns to them while some don’t. Those that do require that the activity started before the bubble withdrew (i.e. the companion reached the location and started the activity before withdrawal).

My character was standing within talk distance of the NPC in both cases.